These studies gather data on pituitary function as it relates to gonadal, thyroid, adrenal, and growth hormone regulation in normal aging men from the Baltimore Longitudinal Study on Aging (BLSA). Recent results have shown that healthy men have changes in pituitary secretion of thyroid stimulating hormone (TSH) which are quite minimal and no apparent change in growth hormone secretion compared with the decrements of secretory capacity reported for less well selected populations.